Results of side by side simultaneous tests to compare the performance of the Moving Target Detector (MID) digital signal processor and that of a newly developed adaptive sliding window detector, the Radar Video Digitizer (RVD-4), are described. The MTD, used with a highly modified FPS-18, employs coherent linear doppler filtering, adaptive thresholding, and a fine grained clutter map which together reject all forms of clutter simultaneously. The RVD-4, which was used with an ASR-7, is a non-linear, non-coherent digital processor. The detection and false alarm performance of both processors in thermal noise was identical. Measured detection and sub-clutter visibility performance of the MTD on controlled aircraft flying in heavy rain, in heavy ground clutter, and at near-zero radial velocity is shown to be superior to that of the RVD-4. MID report data is also shown to be more accurate than the RVD-4 data resulting in improved ARTS-Ill tracker performance when using MID processed data.